A common type of shoulder injury often seen by the practicing physician involves a sprain or separation of the acromioclavicular joint. The acromioclavicular joint, or A-C joint as it is sometimes called, connects the distal end of the clavicle with the underlying acromion which overlies the upper end of the humerus, or upper arm. A sprain or separation is generally caused by a downward blow to the shoulder.
There are various grades of injury to the A-C joint, ranging from sprains to separations, or dislocations. A sprain is defined as an injury to a joint with possible rupture of ligaments but without dislocation. A dislocation, or separation, is defined as an injury to a joint involving rupture of the ligaments and dislocation of the joint. There are various grades of sprains and dislocations ranging from grade I (mild) through grade II (moderate) to grade III (severe).
Depending upon the severity of the injury, surgery may be required to effect proper reparation of the joint. Surgery has the disadvantages of leaving external scars which can be objectionable, especially to female patients. Moreover, with surgery, there are the risks of possible infection, not to mention the need for hospitalization, general anesthesia, and the discomfort associated with the surgical procedure. This is particularly true where a complete separation has occurred thereby requiring the use of a pin and the removal of the pin in a subsequent operation after restoration has been effected.